Well if they don't have a male then they certainly aren't breeding them then. I just did a quick search and found that the two animals arrived as 5-month old cubs and at least one of them is spayed.
I knew that one of them, Kya, was spayed, but I didn't know they came in at five months old from somewhere else, so they weren't born there at least. Now the question is where that somewhere else was. I'll see if I can dig up any more on that. Thanks for your help.